Holcomb rose to his feet, revealing on the table before him a queer, dancing light which he had been studying. He touched something; the light vanished, and simultaneously there came an unnameable change in the appearance of certain of those puzzling crystals. The doctor stepped forward, hand extended, smiling; surely he did not look or act like a prisoner.
“Well, well,” spoke he; “at last! Chick Watson and Harry Wendel! You're very welcome. Was it a long journey?”
His eyes twinkled in the old way. He didn't wait for their replies. He went on:
“Have we solved the Blind Spot? It seems that my pupils never desert me. Let me ask: have you solved the Blind Spot?”
“We've solved nothing, professor. What we have come for is, first, yourself; and second, for the secrets you have found. It is for us to ask—what is the Blind Spot?”
The professor shook his head.
“You were always a poor guesser, Mr. Wendel. Perhaps Chick, now—”
“Put me down as unprepared,” answered Chick. “I'm like Harry—I want to know!”
“Perhaps there are a lot of us in the same fix,” laughed Holcomb. “We, who know more than any men who ever lived, want to know still more! It may be, after all, that we know very little; even though we have solved the problem.” His eyes twinkled again, aggravatingly.
“Tell us, then!” from Harry, on impulse as always. “What is the Blind Spot?”